It is believed that an Exhaust Gas Regulator (xe2x80x9cEGRxe2x80x9d) consists of, among other components, a valve which is inserted into an exhaust gas flow passage. The valve is can be used to control the flow rate of exhaust gas through the passage.
An EGR is also believed to include an actuator shaft that is connected to and manipulates the valve, with a motor that drives the actuator shaft. It is believed that the position of the valve within the exhaust gas flow passage subjects the valve to very high temperatures. It is further believed that the actuator shaft conducts heat energy from the valve to the motor, thereby increasing the operational temperature of the motor. It is yet further believed this temperature increase can adversely effect the performance of the motor and possibly damage the motor.
The invention provides for a regulator valve, preferably an exhaust back pressure regulator valve, alternatively an exhaust gas recirculation valve. The regulator valve has a wall defining a flow passage disposed along a longitudinal axis. A closure member is disposed in the flow passage for rotation about an axis oblique to the longitudinal axis. The closure member is movable to a first position to prevent flow in the flow passage and the closure member is also movable to a second position to permit flow in the flow passage. A motive force device is disposed along the axis and coupled to the closure member by an insulator member. The motive force device is disposed such that it can rotate the closure member between the first position and the second position about the axis. The valve also includes a spacing chamber having an inner wall and an outer wall. The inner wall forms a volume that houses the insulator member, the outer wall of the spacing chamber is coupled to the motive force device and the flow passage.
The present invention provides a method of reducing heat transfer between a hot air passage and a motive force device of a valve disposed at an axis oblique to a longitudinal axis of the flow passage. Preferably, the valve is connected to a driveshaft extending through a wall surface of the flow passage, and the motive force device has an actuating shaft disposed along the longitudinal axis of the flow passage. The method of reducing heat transfer between the flow passage and the motive force device can be achieved by thermally insulating the flow passage from the motive force device. Preferably, the method can be achieved by coupling a chamber having a defined volume to the motive force device and the valve; and connecting the driveshaft to the actuating shaft with an insulator member.